SL/R231: Trickle charge battery?
Thread Starter
Newbie
Joined: Dec 2017
Posts: 3
Likes: 2
2013 SL550
Trickle charge battery?
Hey everyone,
Just a general question regarding winter storage of a 2013 SL550. The car is currently sitting in my garage with a trickle charger that Mercedes has given me for this vehicle, I have it hooked up to the courtesy battery in the truck as this is the electronics hub. My question is, would I need a secondary charger for the engine battery if it will be sitting for most of the winter? Also if i opt to use both would it damage the vehicle in anyway?
Thanks in advance!
Just a general question regarding winter storage of a 2013 SL550. The car is currently sitting in my garage with a trickle charger that Mercedes has given me for this vehicle, I have it hooked up to the courtesy battery in the truck as this is the electronics hub. My question is, would I need a secondary charger for the engine battery if it will be sitting for most of the winter? Also if i opt to use both would it damage the vehicle in anyway?
Thanks in advance!
Junior Member
Joined: Apr 2017
Posts: 35
Likes: 4
'15 X3, '09 Corvette
This is a very good question. Trickle-charging the SL has been brought up before but I still am unsure about the "proper" way to do it. Not sure what you mean by "courtesy battery." I THINK you are proposing to charge the "secondary" battery in the space behind the passenger seat. Seems to me others have said it's better to charge the "main" battery.
It's too bad there isn't a "live" 12V accessory outlet in the vehicle. That would make it very simple.
A search in this forum for "battery" yields this result:
https://mbworld.org/forums/search.php?searchid=20128928
Here's a video on the SLK55. Not sure how it applies to the SL:
Hopefully someone with working knowledge of this will chime in.
It's too bad there isn't a "live" 12V accessory outlet in the vehicle. That would make it very simple.
A search in this forum for "battery" yields this result:
https://mbworld.org/forums/search.php?searchid=20128928
Here's a video on the SLK55. Not sure how it applies to the SL:
Hopefully someone with working knowledge of this will chime in.
MBWorld Fanatic!
Joined: Jan 2016
Posts: 2,336
Likes: 936
From: Brookshire, Texas & Cat Spring, Texas
2019 SL550/2023 EQS 580 SUV
I believe the main battery is used only to start the engine and the secondary battery energizes all other aux. circuits especially the braking system that locks when the engine is off. There is a direct 12v, one way, connection between the batteries. If the main battery is low it can pull from the secondary battery to start the engine but the secondary battery cannot pull from the main battery. For long term storage charging both is the best option though there is no drain on the main battery while the car sits. If I am wrong on this someone correct me please.
Thread Starter
Newbie
Joined: Dec 2017
Posts: 3
Likes: 2
2013 SL550
This is a very good question. Trickle-charging the SL has been brought up before but I still am unsure about the "proper" way to do it. Not sure what you mean by "courtesy battery." I THINK you are proposing to charge the "secondary" battery in the space behind the passenger seat. Seems to me others have said it's better to charge the "main" battery.
It's too bad there isn't a "live" 12V accessory outlet in the vehicle. That would make it very simple.
A search in this forum for "battery" yields this result:
https://mbworld.org/forums/search.php?searchid=20128928
Here's a video on the SLK55. Not sure how it applies to the SL:
https://www.youtube.com/watch?v=gl2A85Imavs
Hopefully someone with working knowledge of this will chime in.
It's too bad there isn't a "live" 12V accessory outlet in the vehicle. That would make it very simple.
A search in this forum for "battery" yields this result:
https://mbworld.org/forums/search.php?searchid=20128928
Here's a video on the SLK55. Not sure how it applies to the SL:
https://www.youtube.com/watch?v=gl2A85Imavs
Hopefully someone with working knowledge of this will chime in.
Thread Starter
Newbie
Joined: Dec 2017
Posts: 3
Likes: 2
2013 SL550
I believe the main battery is used only to start the engine and the secondary battery energizes all other aux. circuits especially the braking system that locks when the engine is off. There is a direct 12v, one way, connection between the batteries. If the main battery is low it can pull from the secondary battery to start the engine but the secondary battery cannot pull from the main battery. For long term storage charging both is the best option though there is no drain on the main battery while the car sits. If I am wrong on this someone correct me please.
